Swainsonine reduces 5-fluorouracil tolerance in the multistage resistance of colorectal cancer cell lines

<p>Abstract</p> <p>Background</p> <p>Drug resistance is a major problem in cancer chemotherapy. Acquisition of chemo-resistance not only reduces the effectiveness of drugs, but also promotes side effects and markedly reduces the patient's quality of life. However, a number of resistance mechanisms have been reported and are thought to be the reason for the difficulties in solving drug-resistance problems.</p> <p>Result</p> <p>To investigate the mechanisms of drug resistance, a set of cell lines with different levels of sensitivity and possessing different mechanisms of resistance to 5-fluorouracil (5-FU) was established from a colorectal cancer cell line. The expression of thymidylate synthase, orotic acid phosphoribosyltransferase and dihydropyrimidine dehydrogenase, which are well known to be related to drug resistance, differed among these cell lines, indicating that these cell lines acquired different resistance mechanisms. However, swainsonine, an inhibitor of N-glycan biosynthesis, reduced 5-FU-tolerance in all resistant cells, whereas the sensitivity of the parental cells was unchanged. Further analysis of the N-glycan profiles of all cell lines showed partial inhibition of biosynthesis and no cytotoxicity at the swainsonine dosage tested.</p> <p>Conclusion</p> <p>These observations suggest that N-linked oligosaccharides affect 5-FU resistance more widely than do drug-resistance related enzymes in colorectal cancer cells, and that the N-glycan could be a universal target for chemotherapy. Further, swainsonine may enhance the performance of chemotherapy by reducing tolerance.</p

Establishment and characterization of a novel treatment‐related neuroendocrine prostate cancer cell line KUCaP13

The prevalence of neuroendocrine prostate cancer (NEPC) arising from adenocarcinoma (AC) upon potent androgen receptor (AR) pathway inhibition is increasing. Deeper understanding of NEPC biology and development of novel therapeutic agents are needed. However, research is hindered by the paucity of research models, especially cell lines developed from NEPC patients. We established a novel NEPC cell line, KUCaP13, from tissue of a patient initially diagnosed with AC which later recurred as NEPC. The cell line has been maintained permanently in vitro under regular cell culture conditions and is amenable to gene engineering with lentivirus. KUCaP13 cells lack the expression of AR and overexpress NEPC-associated genes, including SOX2, EZH2, AURKA, PEG10, POU3F2, ENO2, and FOXA2. Importantly, the cell line maintains the homozygous deletion of CHD1, which was confirmed in the primary AC of the index patient. Loss of heterozygosity of TP53 and PTEN, and an allelic loss of RB1 with a transcriptomic signature compatible with Rb pathway aberration were revealed. Knockdown of PEG10 using shRNA significantly suppressed growth in vivo. Introduction of luciferase allowed serial monitoring of cells implanted orthotopically or in the renal subcapsule. Although H3K27me was reduced by EZH2 inhibition, reversion to AC was not observed. KUCaP13 is the first patient-derived, treatment-related NEPC cell line with triple loss of tumor suppressors critical for NEPC development through lineage plasticity. It could be valuable in research to deepen the understanding of NEPC

Risk stratification for the prognosis of patients with chemoresistant urothelial cancer treated with pembrolizumab

The use of immune checkpoint inhibitors to treat urothelial carcinoma (UC) is increasing rapidly without clear guidance for validated risk stratification. This multicenter retrospective study collected clinicopathological information on 463 patients, and 11 predefined variables were analyzed to develop a multivariate model predicting overall survival (OS). The model was validated using an independent dataset of 292 patients. Patient characteristics and outcomes were well balanced between the discovery and validation cohorts, which had median OS times of 10.2 and 12.5 mo, respectively. The final validated multivariate model was defined by risk scores based on the hazard ratios (HRs) of independent prognostic factors including performance status, site of metastasis, hemoglobin levels, and the neutrophil-to-lymphocyte ratio. The median OS times (95% confidence intervals [CIs]) for the low-, intermediate-, and high-risk groups (discovery cohort) were not yet reached (NYR) (NYR–19.1), 6.8 mo (5.8-8.9), and 2.3 mo (1.2-2.6), respectively. The HRs (95% CI) for OS in the low- and intermediate-risk groups vs the high-risk group were 0.07 (0.04-0.11) and 0.23 (0.15-0.37), respectively. The objective response rates for in the low-, intermediate-, and high-risk groups were 48.3%, 28.8%, and 10.5%, respectively. These differential outcomes were well reproduced in the validation cohort and in patients who received pembrolizumab after perioperative or first-line chemotherapy (N = 584). In conclusion, the present study developed and validated a simple prognostic model predicting the oncological outcomes of pembrolizumab-treated patients with chemoresistant UC. The model provides useful information for external validation, patient counseling, and clinical trial design

High wavelength-resolution Bragg-edge/dip transmission imaging instrument with a supermirror guide-tube coupled to a decoupled thermal-neutron moderator at Hokkaido University Neutron Source

Bragg-edge neutron transmission imaging is one of several useful material characterization tools available at a compact-acceralator driven pulsed-neutron source (a pulsed CANS). Quantitative imaging experiments for crystalline phase, crystallographic texture, and crystallite size have been successfully performed at a pulsed CANS using a coupled (high intensity type) cold-neutron moderator. However, imaging experiments for strain and grain orientation have not been achieved due to the low wavelength-resolution of the coupled moderator. In this study, we demonstrated that both strain imaging using the Bragg-edge transmission method and grain-orientation imaging using the Bragg-dip transmission method are feasible at a pulsed CANS; both types of imaging are made possible with an efficient neutron beam transport system using a supermirror guide-tube combined with a decoupled thermal-neutron moderator (300 K polyethylene), which can supply short neutron pulse. Using this system, we achieved high wavelength-resolution (about 0.5%) Bragg-edge/dip neutron transmission imaging experiments, which correctly visualized the strain values and grain orientations in several polycrystalline materials. On the other hand, it was also found that the neutron flux and the neutron beam angular divergence (L/D) were insufficient with this approach. For this reason, we performed Monte-Carlo simulation studies to investigate a new geometry of moderator system which achieves not only high wavelength-resolution (short pulse width) but also high neutron brightness which is necessary for a high L/D experiment. The simulation results suggest that the most promising candidates use a thin and low-height cold-neutron moderator (20 K methane) with decoupled pre-moderators or poisoned pre-moderators with large solid-angle coverage for fast neutrons emitted from a neutron production target. This system offers higher peak intensity than a coupled moderator for cold neutrons emitted from the highest brightness region on the moderator surface, while achieving narrow pulse widths and decay times as fast as those of decoupled/poisoned moderators

Intracellular localization of mesothelin predicts patient prognosis of extrahepatic bile duct cancer.

Mesothelin is expressed in various types of malignant tumors, and we recently reported that the expression of mesothelin was related to unfavorable patient outcome in pancreatic ductal adenocarcinoma and gastric adenocarcinoma. In this study, we examined the clinicopathological significance of mesothelin expression in extrahepatic bile duct cancer (EHBDCA), especially in terms of its association with the staining pattern. Tissue samples from 61 EHBDCA (16 hilar cholangiocarcinoma, 17 upper bile duct adenocarci-noma, 20 middle bile duct adenocarcinoma and 8 distal bile duct adenocarcinoma) were immunohistochemically examined. The expression levels of mesothelin in tumor cells was classified into the localization of mesothelin in luminal membrane and/or cytoplasm, in addition to high and low according to the staining intensity and proportion as a conventional analysis. 'High-level expression' of mesothelin (47.5%) was statistically correlated with liver metastasis (P=0.013) and poorer patient outcome (P=0.022), while 'luminal membrane positive' of mesothelin (52.5%) was more significantly correlated with liver metastasis (P=0.006), peritoneal metastasis (P=0.024) and unfavorable patient outcome (P=0.017). Moreover, we found that 'cytoplasmic expression' isolated from 'luminal membrane negative' of mesothelin represented the best patient prognosis throughout this study. We describe the expression pattern level of mesothelin, i.e., in luminal membrane or cytoplasm both high and low level, evidently indicate the patient prognosis of EHBDCA, suggesting the pivotal role of mesothelin in cancer promotion depending on its intracellular localization

C-ERC/mesothelin provokes lymphatic invasion of colorectal adenocarcinoma

Background Lymph node metastasis is a key event of colorectal cancer (CRC) progression. Mesothelin is expressed in various types of malignant tumor and associated with an unfavorable prognosis. The full-length mesothelin (Full-ERC) is cleaved by protease into membrane-bound C-ERC/mesothelin and N-ERC/mesothelin which is secreted into the blood. The aim of this study was to examine the biological role of mesothelin in CRC by clinicopathological analysis and in vitro lymphatic invasion assay. Methods Ninety-one cases of CRC specimens were immunohistochemically examined and the localization of mesothelin in luminal membrane and/or cytoplasm was also evaluated. Lymphatic invasion assay was also performed using the human CRC cell line, WiDr, which was transfected with Full-, N- and C-ERC/mesothelin expression plasmids (Full-WiDr, N-WiDr and C-WiDr). Results Immunohistochemically, "luminal membrane positive" of mesothelin was identified in 37.4 %, and correlated with lymphatic permeation and lymph node metastasis, but not with patients' prognosis. Interestingly, among the patients with lymph node metastasis (N = 38), "luminal membrane positive" of mesothelin significantly correlated with unfavorable patients' outcome. In addition, lymphatic invasion assay revealed that Full-WiDr and C-WiDr more significantly invaded human lymphatic endothelial cells than the Mock-WiDr (P < 0.01). Conclusion The luminal membrane expression of mesothelin was associated with unfavorable prognosis of CRC patients with lymph nodemetastasis. Moreover, this is the first report to prove the biological function of C-ERC/mesothelin associated with lymphatic invasion of cancer in vitro

Predictive factors for microscopic portal venous invasion and the place of anatomic liver resection

Background: The aims of this study were to investigate predictive factors for microscopic portal venous invasion (mPVI) in hepatocellular carcinoma (HCC) and whether anatomical liver resection (ALR) was useful in such cases. Methods: We analyzed 852 patients with HCC without macroscopic portal venous invasion who were treated at our hospital between January 1990 and May 2014. These patients were stratified into a microscopic portal venous invasion group (mPVI group; n = 153) and non-microscopic portal venous invasion group (NmPVI group; n = 699). Results: PIVKA-II ≥100 mAU/ml, a tumor size ≥5 cm, a confluent lesion, and poor differentiation were found to be independent risk factors for mPVI. Among the mPVI group who had single HCC under 5 cm, serum albumin level <4.0 g/dl, PIVKA-II ≥100 mAU/ml, a positive surgical margin, and non-ALR (NALR) were independent unfavorable prognostic factors for overall survival (OS). PIVKA-II ≥100 mAU/ml, a positive surgical margin and NALR were independent unfavorable prognostic factors for relapse-free survival (RFS). ALR was significantly favorable factor for both OS and RFS of the mPVI group who had single HCC under 5 cm. Conclusions: Even if no portal venous invasion is detectable in HCC patients preoperatively, a PIVKA-II ≥100 mAU/ml, tumor size ≥5 cm, and a confluent lesion indicate a high risk of mPVI. ALR should be considered for the patients with these characteristics because it is a favorable prognostic factor in these cases with mPVI